Optically controlled contradirectional coupler

A multiple-quantum-well optically controlled contradirectional coupler has been realized following the design criteria discussed here and elucidated by the simulations. Our room-temperature experiments show a power-dependent contradirectional coupling condition, allowing optically controlled sw itching between two output channels with control energies on the order of 1 pJ, and at a wavelength around 1.55 mu m. The device is treated theoretically by a coupled-mode analysis in order to compute the linear and nonlinear transmission spectra at the hto output ports. The effects induced by the propagation of intense control beams are modeled using a nonlinear two-dimensional beam propagation method.